1. Field of the Invention
This invention relates to dust removal systems, shop vacuum cleaners, dust separation devices and auxiliary containers to receive sawdust, planer shavings and other particles and materials collected by dust removal systems and shop vacuum cleaners.
2. The Prior Art
Shop vacuum cleaners and a substantial variety of sizes and configurations of dust removal systems are widely used in home workshops, cabinet shops and commercial woodworking facilities for the collection and removal of sawdust, planer chips, sanding dust, and other dust and particulate matter produced during operation of such facilities. Typical shop vacuum cleaners draw air and waste through a flexible hose into a bucket-like waste collection chamber. There the air is drawn through a filter, typically a pleated filter of nonwoven fibrous material, which catches most of the waste material, allowing relatively clean air to be discharged. Dust collectors typically utilize a squirrel cage fan that draws air and debris through the fan and into a sleeve-like structure oriented vertically so that a cloth waste collection bag can hang below the structure and air can exit through a cloth bag attached to, and which inflated during use above, the sleeve. The capacity of each of these devices is limited to the capacity of the rigid bucket-like container in the case of the shop vacuum and the lower waste receiving bag or bags in the case of the dust collector.
Efforts have been undertaken to increase the quantity of sawdust and other waste that can be collected using such devices (without emptying the waste reservoirs) by drawing the air and collected debris first through or adjacent to an auxiliary waste collection receptacle into which some of the waste falls, thereby increasing the overall capacity of the system by the volume of the auxiliary receptacle.
One widely available device to accomplish this is a replacement lid intended to be positioned on top of a trash container or other receptacle having an open top and is described in U.S. Pat. No. 5,525,396. This lid has entrance and exit holes for tubing and a baffle between the entrance and exit so that some of the dust and other debris entrained in an air stream passing through the device falls down into the trash container or other receptacle on which the device rests. Because this replacement lid is opaque and it must be used on a rigid container (rather than, for instance, with a cloth bag), the lid must be removed to determine whether the container on which it is used is full.